diff options
Diffstat (limited to 'kernel/signal.c')
| -rw-r--r-- | kernel/signal.c | 34 |
1 files changed, 24 insertions, 10 deletions
diff --git a/kernel/signal.c b/kernel/signal.c index 7ed8d5304bec..1921ffdc5e77 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -23,6 +23,10 @@ #include <linux/ptrace.h> #include <linux/signal.h> #include <linux/capability.h> +#include <linux/freezer.h> +#include <linux/pid_namespace.h> +#include <linux/nsproxy.h> + #include <asm/param.h> #include <asm/uaccess.h> #include <asm/unistd.h> @@ -33,7 +37,7 @@ * SLAB caches for signal bits. */ -static kmem_cache_t *sigqueue_cachep; +static struct kmem_cache *sigqueue_cachep; /* * In POSIX a signal is sent either to a specific thread (Linux task) @@ -267,18 +271,25 @@ static struct sigqueue *__sigqueue_alloc(struct task_struct *t, gfp_t flags, int override_rlimit) { struct sigqueue *q = NULL; + struct user_struct *user; - atomic_inc(&t->user->sigpending); + /* + * In order to avoid problems with "switch_user()", we want to make + * sure that the compiler doesn't re-load "t->user" + */ + user = t->user; + barrier(); + atomic_inc(&user->sigpending); if (override_rlimit || - atomic_read(&t->user->sigpending) <= + atomic_read(&user->sigpending) <= t->signal->rlim[RLIMIT_SIGPENDING].rlim_cur) q = kmem_cache_alloc(sigqueue_cachep, flags); if (unlikely(q == NULL)) { - atomic_dec(&t->user->sigpending); + atomic_dec(&user->sigpending); } else { INIT_LIST_HEAD(&q->list); q->flags = 0; - q->user = get_uid(t->user); + q->user = get_uid(user); } return(q); } @@ -575,7 +586,7 @@ static int check_kill_permission(int sig, struct siginfo *info, error = -EPERM; if ((info == SEND_SIG_NOINFO || (!is_si_special(info) && SI_FROMUSER(info))) && ((sig != SIGCONT) || - (current->signal->session != t->signal->session)) + (process_session(current) != process_session(t))) && (current->euid ^ t->suid) && (current->euid ^ t->uid) && (current->uid ^ t->suid) && (current->uid ^ t->uid) && !capable(CAP_KILL)) @@ -1126,8 +1137,7 @@ int kill_pid_info(int sig, struct siginfo *info, struct pid *pid) return error; } -int -kill_proc_info(int sig, struct siginfo *info, pid_t pid) +static int kill_proc_info(int sig, struct siginfo *info, pid_t pid) { int error; rcu_read_lock(); @@ -1870,8 +1880,12 @@ relock: if (sig_kernel_ignore(signr)) /* Default is nothing. */ continue; - /* Init gets no signals it doesn't want. */ - if (current == child_reaper) + /* + * Init of a pid space gets no signals it doesn't want from + * within that pid space. It can of course get signals from + * its parent pid space. + */ + if (current == child_reaper(current)) continue; if (sig_kernel_stop(signr)) { |